RV.Net Open Roads Forum: Towing: Do you Sway??

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Towing

Open Roads Forum  >  Towing

 > Do you Sway??

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next
Sponsored By:
Kusani

Tennessee

Moderator

Joined: 10/12/2001

View Profile


Offline
Posted: 08/19/02 05:48pm Link  |  Print  |  Notify Moderator

Commercial....[emoticon]

PullToy

USA

Senior Member

Joined: 09/24/2001

View Profile


Offline
Posted: 08/19/02 11:28pm Link  |  Print  |  Notify Moderator

Well...OK... now for a different view. A bit of research will show that there is one and only one "cause" of oscillation type sway. That is the fact that TTs have to be hitched behind the rear axle. It is not tongue weight, leveling, tire pressures or the rest of the urban myths. When was the last time anyone heard a fiver hauler saying he cured a "sway problem" by leveling the trailer? They rarely "sway" no matter how unlevel (it sure causes other problems however) or how messed up the loading. That's because the root cause has been removed.

To be sure, all those things mentioned before like tongue weight etc... will minimize sway and can turn a lousy tower into a nice one. It doesn't change the fact that the root cause is still there. Adjusting all those things is just making the best of the situation. But to say that any of those things is the "cause" of sway is flat wrong. It also leads people to think they are "curing" sway by leveling or loading or whatever.

I had a brother-in-law who drove a Datsun 510 on which the carb would routinely build up ice (under certain conditions) at cruising speeds. The ice would build until it choked itself to a stop. When the car would finally die, he would pull over on the shoulder and get under the hood. He would wiggle this certain wire for a time and then get back in and the car would start up just fine. He was, of course, simply taking up time until the ice melted. But he was very convinced that wiggling that wire was what solved the problem... after all, the car would start again if he wiggled the wire long enough. After watching this for a few times, I turned the snorkle on the air cleaner around and it never died again. I don't know how many years he had been wiggling that poor wire.

I'm not saying that getting the setup correctly won't be the best for any rig, but if people continue to think that tongue weight, or this or that, "causes" sway, things will never improve and we'll keep reading stories of TT's sliding down the road with their feet in the air. Stay safe out there....


T_Bone

Arizona

Senior Member

Joined: 09/20/2001

View Profile



Posted: 08/20/02 01:05am Link  |  Print  |  Notify Moderator

Comparing apples with apples. A 5'er is less prone to sway because of the hitch point. Can a 5'er sway? You bet! It just takes more to sway a 5'er or gooseneck than it does a TT. Load a 5'er with 2000lbs extra on one side and see what happens.

Does anyone see a semi going down the hi-way with 40,000lb pipe loaded on one side of a flatbed? Can't be for weight distribution on the trailer as when there hauling 80,000lbs, one side of the trailer carrys 40000lbs.
No they don't do that as they will load the 40000lb pipe in the center of the trailer. why? To keep the trailer from swaying and other considerations.

Were not talking about 5'ers swaying though and were addressing TT swaying.

TT sway is a reality caused from the hitching point, trailer level and load weight. We can't do anything about the hitch point but we can do something about trailer level and load placement.

Bumper pull trailers are the most unforgiving for mistakes of all trailers types. Can they be pulled safely? Sure they can with good prethought.

You can't cure 100% of sway on "any" type of trailer. Some trailers just sway less that others.

E-mail any trailer mfg and ask this question and you'll get the same answer, load placement and level does matter on all trailer types.




T_Bone
02 F350, 4x6, CC, DRW, PSD, 6spd, 3:73
32ft Serria 10yr 100% Solar
Please do not trust everything you read on the internet. Use only valid engineering information from well established Companys.
Buy UNION Work UNION
It pays off in the long run !

Kusani

Tennessee

Moderator

Joined: 10/12/2001

View Profile


Offline
Posted: 08/20/02 08:26am Link  |  Print  |  Notify Moderator

TBone...

Also, if I moved the dual wheels of my TT to the back of my TT (like the 18 wheelers) and hooked on directly over my rear axle of my tow vehicle, I would elimiate most of the sway also. People that compare towing rvs to 18 wheelers aren't looking at the differences in the setups. One really can't compare other than to look at the differences, not the similiarities, imo.

Happy rv'in.

PullToy

USA

Senior Member

Joined: 09/24/2001

View Profile


Offline
Posted: 08/20/02 10:58am Link  |  Print  |  Notify Moderator

T-Bone, I never said that loading and leveling weren't a "factor." In fact I said they were. You stated that they were the "cause" of sway. You missed the point. Fivers don't sway because.... why? If you think it's because they're level... look again. A fiver's hitch point is at, or in front of, the rear axle. This eliminates the "lever arm" created by the distance between the hitch ball and the rear axle. It is the lever arm that provides the pendulum type effect which IS oscillating sway. If the arm is gone... so is the sway. I'm talking about the oscillating type of sway that builds and builds until the rig is lost, not the slight movement when the semi goes past. Fivers do not exhibit oscillating sway. Why is that? You don't have to believe me... just look around the web. But you answered the question when you said fivers are "less prone to sway" because of the hitch point. Isn't that the same thing as saying that eliminating the lever arm gets rid of sway? If leveling and weight distribution are the causes of sway, we should be able to balance and level the TTs and throw away the sway controls. Some TTs that are level and balanced, still exhibit sway (I've had 3 that did and the presence of sway controls on the majority of TTs indicates that they exhibit sway too.) ...so, something else must be the cause.

You said that there was nothing that could be done about being hitched behind the axle. That is not correct. There are at least two solutions.

*This Message was edited on 20-Aug-02 04:22 PM by Pulltoy*


T_Bone

Arizona

Senior Member

Joined: 09/20/2001

View Profile



Posted: 08/21/02 02:39am Link  |  Print  |  Notify Moderator

Hi Kusani,

Moving the axles back helps a triffic amount but also increases the tongue weight alot. My water trailer is set-up that way. The trailer had a 16ft flatdeck axles placed on the 2/3 rule and it was cut before the axles and another 8ft was added. That trailer has almost no sway but also has about 6000lbs tongue weight when loaded.

The semi refference was only to that if it was not loaded correct even a semi can have sway.

----------------------------------------------

Hi PullToy,

They are a cause of sway. Take a TT that has very little sway, then load it wrong and out of level will cause the trailer to sway. I'm sticking too that as I've seen it done a many times. I myself have loaded a trailer wrong and paid the price of creating sway so it can be done.

I do agree the root cause is the lever. And I agree that a hicth point over the axle is the best of all hitch points but I stick with if a trailer is not loaded correct and in level it does not matter what hitch point you have, the trialer can sway.

An example would be a 5'er hitch point, empty flatbed, then quickly jerk the wheel to the left, then jerk it right. What happens? The trailer will whip. Why? We have not gotten rid of our lever but just changed it's lever point.

Solutions? I will say they improve the sway promlem but not eliminate it as all trailers have sway, some just less than others.



rx2tee

Mojave Desert

Senior Member

Joined: 05/20/2002

View Profile


Offline
Posted: 08/21/02 06:46am Link  |  Print  |  Notify Moderator

I agree with Pulltoy. Having experienced a bad sway problem with a glider trailer being pulled by a Bronco II. Maybe the tongue weight was off, I don’t know. What I do know is how scary it is when a trailer starts trying to pry the front end of your tow vehicle from side to side. Adding throttle would dampen the oscillation but the increased speed would just make the next oscillation that much worse. It seems that the “lever," is the distance from the pivot point of the hitch, to the center of the rear axle of the tow vehicle. The shorter the wheelbase of the tow vehicle, the greater the mechanical advantage for this lever.

A friend of mine had an incident with a car hauler trailer being towed with a 12-passenger van. Now the van does have a long wheelbase, but it also has a lot of distance from the rear axle to the hitch pivot point. This trailer ended up swinging so far from side to side that the tires were ruined from skidding sideways and replaced in order to continue.

I would rather tow with a setup that allows a safe trip even if the tongue weight happens to be less than ideal. That way, I don’t have to worry about a stretch of bumps on a downhill curve setting up an oscillation that starts a white-knuckle ride.


*This Message was edited on 21-Aug-02 06:48 AM by rx2tee*



2002 4x4 f-250 LB 7.3 Powerstroke
6-spd manual 3.73 axle
Gemtop
Rhinoliner
Pullrite hch, Prodigy Bk. Ctl.
Jayco 25RKS
Randy & Colleen

chuckb1

louisville,co usa

Senior Member

Joined: 07/24/2002

View Profile


Offline
Posted: 08/21/02 07:09am Link  |  Print  |  Notify Moderator

Why on earth would you tow anything with a Bronco II ? Don't they have a bad reputation for rollover on their own?

PullToy

USA

Senior Member

Joined: 09/24/2001

View Profile


Offline
Posted: 08/21/02 11:24am Link  |  Print  |  Notify Moderator

One last question T-Bone: My TT is level and loaded correctly, my tire pressures are spot on and I have a long WB tow truck. Can I throw my sway control away?



*This Message was edited on 21-Aug-02 11:28 AM by Pulltoy*


rx2tee

Mojave Desert

Senior Member

Joined: 05/20/2002

View Profile


Offline
Posted: 08/21/02 05:24pm Link  |  Print  |  Notify Moderator

I realize the Bronco II, which I put 225k miles on and still own, isn't the best tow vehicle. Lots of miles with no real handling surprises. Except for the time I retrieved a friend and his sailplane. One look at short wheelbase vehicle like a Jeep or Bronco II should tell you not to ask it to change direction too quickly at speed. It was probably a worse case scenerio, but I have seen much larger rigs swaying so bad that I was almost afraid to pass.

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next

Open Roads Forum  >  Towing

 > Do you Sway??
Search:   Advanced Search

Search only in Towing


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.